Establishment of Perennial Groundcovers for Corn-Based Bioenergy Production Systems.

With increasing removal of corn stover for either cellulosic biofuels or livestock bedding and feedstuffs, there exists a greater need to ensure natural resources-related issues such as soil erosion, nitrate leaching, and loss of organic matter content are appropriately managed.  Perennial groundcover offers a tenable solution for alleviating these problems associated with removal of corn stover from conventional cropping systems.  We conducted a field study to ascertain the expected cost of perennial groundcover establishment on the primary crop of economic interest and assess success of groundcover establishment during a soybean or corn crop.  To test this concept, we established Kentucky bluegrass and creeping red fescue as perennial covers concurrently with both corn and soybean crops and documented their impacts on crop phenology, leaf area index (LAI), normalized difference vegetation index (NDVI), stand density, yield components, grain yield and C/N.  Corn and soybean in the conventional production system yielded on average 13,003 and 3,379 kg ha^-1, respectively, 30 and 84% greater than when grown with the perennial cover crop treatments. Although these perennial groundcover treatments impacted grain yield negatively, they did not affect expected ethanol yield (.42 liter kg^-1 average for bare soil and perennial cover treatments).   These preliminary results indicate that up-front economic concessions must be made to allow for the establishment and subsequent natural resources benefits of perennial groundcover in row crop production.